The woman was found hanging from the ceiling fan of her flat last evening by a police team, they said.
"When her roommates came back from office, they found the door of the flat locked from inside. They informed the police and a team broke open the door. They found her hanging from the fan," Sector 58 Police Station in-charge Anil Pratap Singh said.
The woman in a suicide note claimed that she took the extreme step after she came to know that a man, who she was having an affair with for the last two years, was getting married, the officer said.
The police will question the man after the woman's parents file a complaint, he said.